The photoinduced dynamics of isolated n‐hydroxyquinoline (nHQ) molecules (n=6,8) was investigated in femtosecond pump‐probe experiments. A qualitative difference was found between 8HQ and 6HQ. After an initial rapid decay corresponding to the departure of the initial wavepacket out of the Franck‐Condon region of the excitation, the 8HQ probe signal decays to zero in 0.37 ps whereas a much longer time constant of 10.4 ps is observed in 6HQ. This interrogates on the role played by the intramolecular H‐bond N HO which is at play the 8HQ molecule. Ab‐initio were performed at the MCSCF/aug‐cc‐pVDZ level on the 8HQ molecule to help the discussion. A complex energy landscape was found, which includes a conical intersection.